Objective The nucleolar protein PES1(Pescadillo homolog 1)plays critical roles in ribosome biogenesis and cell cycle regulation,yet its involvement in cellular senescence remains poorly understood.This study aimed to ...Objective The nucleolar protein PES1(Pescadillo homolog 1)plays critical roles in ribosome biogenesis and cell cycle regulation,yet its involvement in cellular senescence remains poorly understood.This study aimed to comprehensively investigate the functional consequences of PES1 suppression in cellular senescence and elucidate the molecular mechanisms underlying its regulatory role.Methods Initially,we assessed PES1 expression patterns in two distinct senescence models:replicative senescent mouse embryonic fibroblasts(MEFs)and doxorubicin-induced senescent human hepatocellular carcinoma HepG2 cells.Subsequently,PES1 expression was specifically downregulated using siRNA-mediated knockdown in these cell lines as well as additional relevant cell types.Cellular proliferation and senescence were assessed by EdU incorporation and SA-β-gal staining assays,respectively.The expression of senescence-associated proteins(p53,p21,and Rb)and SASP factors(IL-6,IL-1β,and IL-8)were analyzed by Western blot or qPCR.Furthermore,Northern blot and immunofluorescence were employed to evaluate pre-rRNA processing and nucleolar morphology.Results PES1 expression was significantly downregulated in senescent MEFs and HepG2 cells.PES1 knockdown resulted in decreased EdU-positive cells and increased SA-β-gal-positive cells,indicating proliferation inhibition and senescence induction.Mechanistically,PES1 suppression activated the p53-p21 pathway without affecting Rb expression,while upregulating IL-6,IL-1β,and IL-8 production.Notably,PES1 depletion impaired pre-rRNA maturation and induced nucleolar stress,as evidenced by aberrant nucleolar morphology.Conclusion Our findings demonstrate that PES1 deficiency triggers nucleolar stress and promotes p53-dependent(but Rb-independent)cellular senescence,highlighting its crucial role in maintaining nucleolar homeostasis and regulating senescence-associated pathways.展开更多
OBJECTIVE To explored the potential of pharmacological stabilization and reactivation of p53 for targeted cancer therapies.METHODS The cytotoxicity of a potent Cyclophilin A(CypA)inhibitor HL001 was tasted against a p...OBJECTIVE To explored the potential of pharmacological stabilization and reactivation of p53 for targeted cancer therapies.METHODS The cytotoxicity of a potent Cyclophilin A(CypA)inhibitor HL001 was tasted against a panel of cancer cell lines.The genotypes and activation of p53 were compared with the cytotoxicity profile of HL001.Two-dimensional(2D)PAGE analysis was performed to investigate differentially expressed proteins that involves in the anti-proliferation effects of HL001.Pull-down and Co-IP were used to confirmed the new identified PPI between CypA and G3BP1 and orthotopic animal model of lung cancer was used to tested the anti-tumor activity of HL001 in vivo.RESULTS We identify a novel CypA small molecule inhibitor HL001 that induces non-small cell lung cancer(NSCLC)cell cycle arrest and apoptosis via restoring p53 expression.We find that HL001 stabilizes p53 through inhibiting the MDM2-mediated p53 ubiquitination.Further mechanistic studies reveal that the downregulation of G3BP1 and the induction of reactive oxygen species and DNA damage by HL001 contribute to p53 stabilization.Surprisingly,HL001 selectively suppresses tumor growth in p53wildtype NSCLC harboring Arg72 homozygous alleles(p53-72R)through disrupting interaction between MDM2 and p53-72R in a CypA dependent manner.Moreover,combining HL001 with cisplatin synergistically enhance tumor regression in orthotopic NSCLC mouse model.CONCLUSION Pharmacologic inhibition of CypA offers a potential therapeutic strategy via specific activation of p53-72R in NSCLC.展开更多
ATM protein anticipates in the initiation of the DNA repair signal pathway and also mediates cell cycle arrest and repair. ATM deficiency predictably results in radiosensitivity, germ cell degeneration, chromosomal in...ATM protein anticipates in the initiation of the DNA repair signal pathway and also mediates cell cycle arrest and repair. ATM deficiency predictably results in radiosensitivity, germ cell degeneration, chromosomal instability, immunodeficiency, and an extreme predisposition to tumors. Moreover, studies found that ATM is the upstream gene of the p53 pathway and would phosphorylate p53 directly after DNA damage, which would suppress tumorigenesis. Expression of ATM and p53 in 167 pancreatic cancer and 101 control specimens, benign lesions, and normal pancreata were detected by high-throughput tissue microarray and immunohistochemistry while seeking the role of ATM in the initiation and development of pancreatic carcinoma as well as its relationship with p53. We found that the positive rates of ATM and p53 expression in pancreatic carcinoma and its relative control specimen were 67.7% (113/167) and 82.2% (83/101) (P<0.05) and 57.5% (96/167) and 5.0% (5/101) (P<0.01), respectively. ATM positive staining is significantly relative to age and infiltration (P<0.05), while the expression of p53 was significantly associated with tumor differentiation, lymph node metastasis, and nerve infiltration (P<0.05). Expression of ATM and p53 was positively correlated. These findings suggest that expression of ATM deficiency may increase the transformative ability of pancreatic cancer cells. ATM may also cooperate with p53 in the repair of cell damage.展开更多
CDC25A, TSSK3 and P53 expressions in vitro in cultured sertoli cells after FSH treatment were studied in order to provide some data for further researches of spermatogenesis. Different concentrations of FSH（0, 0.01, ...CDC25A, TSSK3 and P53 expressions in vitro in cultured sertoli cells after FSH treatment were studied in order to provide some data for further researches of spermatogenesis. Different concentrations of FSH（0, 0.01, 0.02, 0.04, and 0.08 IU ·m L^-1） were used to treat sertoli cells cultured in vitro. The expression of CDC25 A, TSSK3 and P53 was determined by real-time-PCR at 6 h,12 h and 24 h after FSH treatment of sertoli cells. The results showed that FSH had no significant effect on expression of CDC25A（p〈0.05）, could significantly improve the expression of TSSK3 and P53（p0.05）, and had no significant effect on expression of CDC25 A in sertoli cells, but it could significantly improve the expression of TSSK3. CDC25 A was likely to play a role in other signaling pathways in sertoli cells. Within the range of certain concentration of FSH, TSSK3 in sertoli cells had the highest expression at about 24 h. TSSK3 protein produced in sertoli cells was likely to play an important role in substrate-level phosphorylationbe in meiosis and mitosis of spermatogenic cells. FSH could promote P53 expression and the highest expression was at about 12 h, and P53 might control the division of spermatogenic cells as well as sertoli cells.展开更多
文摘Objective The nucleolar protein PES1(Pescadillo homolog 1)plays critical roles in ribosome biogenesis and cell cycle regulation,yet its involvement in cellular senescence remains poorly understood.This study aimed to comprehensively investigate the functional consequences of PES1 suppression in cellular senescence and elucidate the molecular mechanisms underlying its regulatory role.Methods Initially,we assessed PES1 expression patterns in two distinct senescence models:replicative senescent mouse embryonic fibroblasts(MEFs)and doxorubicin-induced senescent human hepatocellular carcinoma HepG2 cells.Subsequently,PES1 expression was specifically downregulated using siRNA-mediated knockdown in these cell lines as well as additional relevant cell types.Cellular proliferation and senescence were assessed by EdU incorporation and SA-β-gal staining assays,respectively.The expression of senescence-associated proteins(p53,p21,and Rb)and SASP factors(IL-6,IL-1β,and IL-8)were analyzed by Western blot or qPCR.Furthermore,Northern blot and immunofluorescence were employed to evaluate pre-rRNA processing and nucleolar morphology.Results PES1 expression was significantly downregulated in senescent MEFs and HepG2 cells.PES1 knockdown resulted in decreased EdU-positive cells and increased SA-β-gal-positive cells,indicating proliferation inhibition and senescence induction.Mechanistically,PES1 suppression activated the p53-p21 pathway without affecting Rb expression,while upregulating IL-6,IL-1β,and IL-8 production.Notably,PES1 depletion impaired pre-rRNA maturation and induced nucleolar stress,as evidenced by aberrant nucleolar morphology.Conclusion Our findings demonstrate that PES1 deficiency triggers nucleolar stress and promotes p53-dependent(but Rb-independent)cellular senescence,highlighting its crucial role in maintaining nucleolar homeostasis and regulating senescence-associated pathways.
基金supported by National Natural Science Foundation of China(31371485,81402482,91313303 and 81573020)CAS Key Laboratory of Receptor Research,the Shanghai Committee of Science and Technology(15431902000)
文摘OBJECTIVE To explored the potential of pharmacological stabilization and reactivation of p53 for targeted cancer therapies.METHODS The cytotoxicity of a potent Cyclophilin A(CypA)inhibitor HL001 was tasted against a panel of cancer cell lines.The genotypes and activation of p53 were compared with the cytotoxicity profile of HL001.Two-dimensional(2D)PAGE analysis was performed to investigate differentially expressed proteins that involves in the anti-proliferation effects of HL001.Pull-down and Co-IP were used to confirmed the new identified PPI between CypA and G3BP1 and orthotopic animal model of lung cancer was used to tested the anti-tumor activity of HL001 in vivo.RESULTS We identify a novel CypA small molecule inhibitor HL001 that induces non-small cell lung cancer(NSCLC)cell cycle arrest and apoptosis via restoring p53 expression.We find that HL001 stabilizes p53 through inhibiting the MDM2-mediated p53 ubiquitination.Further mechanistic studies reveal that the downregulation of G3BP1 and the induction of reactive oxygen species and DNA damage by HL001 contribute to p53 stabilization.Surprisingly,HL001 selectively suppresses tumor growth in p53wildtype NSCLC harboring Arg72 homozygous alleles(p53-72R)through disrupting interaction between MDM2 and p53-72R in a CypA dependent manner.Moreover,combining HL001 with cisplatin synergistically enhance tumor regression in orthotopic NSCLC mouse model.CONCLUSION Pharmacologic inhibition of CypA offers a potential therapeutic strategy via specific activation of p53-72R in NSCLC.
文摘ATM protein anticipates in the initiation of the DNA repair signal pathway and also mediates cell cycle arrest and repair. ATM deficiency predictably results in radiosensitivity, germ cell degeneration, chromosomal instability, immunodeficiency, and an extreme predisposition to tumors. Moreover, studies found that ATM is the upstream gene of the p53 pathway and would phosphorylate p53 directly after DNA damage, which would suppress tumorigenesis. Expression of ATM and p53 in 167 pancreatic cancer and 101 control specimens, benign lesions, and normal pancreata were detected by high-throughput tissue microarray and immunohistochemistry while seeking the role of ATM in the initiation and development of pancreatic carcinoma as well as its relationship with p53. We found that the positive rates of ATM and p53 expression in pancreatic carcinoma and its relative control specimen were 67.7% (113/167) and 82.2% (83/101) (P<0.05) and 57.5% (96/167) and 5.0% (5/101) (P<0.01), respectively. ATM positive staining is significantly relative to age and infiltration (P<0.05), while the expression of p53 was significantly associated with tumor differentiation, lymph node metastasis, and nerve infiltration (P<0.05). Expression of ATM and p53 was positively correlated. These findings suggest that expression of ATM deficiency may increase the transformative ability of pancreatic cancer cells. ATM may also cooperate with p53 in the repair of cell damage.
基金Supported by the National International Scientific and Technological Cooperation Project(2011DFA30760-2-1)Fund of Key Laboratory of Northeast Agricultural University,China(GXZDSYS-2012-07)
文摘CDC25A, TSSK3 and P53 expressions in vitro in cultured sertoli cells after FSH treatment were studied in order to provide some data for further researches of spermatogenesis. Different concentrations of FSH（0, 0.01, 0.02, 0.04, and 0.08 IU ·m L^-1） were used to treat sertoli cells cultured in vitro. The expression of CDC25 A, TSSK3 and P53 was determined by real-time-PCR at 6 h,12 h and 24 h after FSH treatment of sertoli cells. The results showed that FSH had no significant effect on expression of CDC25A（p〈0.05）, could significantly improve the expression of TSSK3 and P53（p0.05）, and had no significant effect on expression of CDC25 A in sertoli cells, but it could significantly improve the expression of TSSK3. CDC25 A was likely to play a role in other signaling pathways in sertoli cells. Within the range of certain concentration of FSH, TSSK3 in sertoli cells had the highest expression at about 24 h. TSSK3 protein produced in sertoli cells was likely to play an important role in substrate-level phosphorylationbe in meiosis and mitosis of spermatogenic cells. FSH could promote P53 expression and the highest expression was at about 12 h, and P53 might control the division of spermatogenic cells as well as sertoli cells.
